APOD and General Astronomy Discussion Forum
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Is no one else getting the water melon effect ? I have seen this stereo pair twice and saw the same thing. As for viewing these stereo pairs, I just relax my eyes and allow the two images to drift towards the center. Then there are three with the 3D effect locked in the center. Forcing my eyes to cross does not work for me.Coil_Smoke wrote:There must be some distortion in generating this stereo pair. When I get the images to merge, a very elongated ' water melon ' shape appears. Like viewing a water melon end on. I have seen no other images that show Pluto is shaped like this.
No, the effect is real. Probably the result of this not being a true stereo pair, but rather two images made at different times, with both spacecraft motion and planetary rotation combined. Also, the spacing is very large, which gives a diorama effect that emphasizes the distortion.Coil_Smoke wrote:Is no one else getting the water melon effect ? I have seen this stereo pair twice and saw the same thing.Coil_Smoke wrote:There must be some distortion in generating this stereo pair. When I get the images to merge, a very elongated ' water melon ' shape appears. Like viewing a water melon end on. I have seen no other images that show Pluto is shaped like this.
Good heavens! I'm not going to try that. But what I learned long ago that I CAN do and HAVE learned to do, is hold up either hand, flat --- and have either the little finger by itself, or the next finger by itself bend at right angles. Just takes practice!Chris Peterson wrote:stereouseless wrote: You can learn to point your eyes independently (like a chameleon) and amaze your friends and possibly advance a career in comedy... all harmlessly.
Without special training, normal eyes can go from very cross-eyed (as when you look at a close object) to parallel (as when you look at an object at infinity). Normal stereo pairs need to be of a size such that when you look at them, you aren't trying to drive your eyes outwards beyond parallel (which is physically possible, but difficult without practice).geckzilla wrote:I can do the cross-eyed version (Henry's) but not the wall-eyed one (APOD). I've always found cross-eye easier to do. I can only get 1/3 to 1/2 of the way there the other way.
Yes, it's the same. But with the random dot stereogram, you don't have to change the direction your eyes are pointing very much, so you don't have that major decouple between focus and position.Ron-Astro Pharmacist wrote:I'm having the same difficulty as some of the others. Is the technique similar to looking at a stereogram?
I can make out the star but not a stereo Pluto.
Yes. I was seeing the star(s) up above the background coming out of the image. I was able to start to view the stereo Pluto as a series of three objects but it hasn't come into 3D yet. I think it's easier for me to spread my gaze outward as you are talking about but more difficult to cross them. It does take some training. Looking at a variety of stereograms seems to be training my eye muscles to do what I want them to.Chris Peterson wrote:Yes, it's the same. But with the random dot stereogram, you don't have to change the direction your eyes are pointing very much, so you don't have that major decouple between focus and position.Ron-Astro Pharmacist wrote:I'm having the same difficulty as some of the others. Is the technique similar to looking at a stereogram?
I can make out the star but not a stereo Pluto.
Do you see the star coming out of the image or going into it? If the first, you are deviating your eyes slightly outwards, like you need to do in order to view today's APOD. If you're seeing the star sinking inwards, you're viewing the stereogram cross-eyed, the way you need to view Henry's switched version.
Wishfull thinking - that has do another set of muscles but this is still a good for seeing in 3D.As a rule, you can significantly blur one side of a stereogram and see little loss of detail. Our brain takes the high frequency information from the sharp side and combines it with the 3D information from the pair. A cute trick. Personally, I find it very difficult to detect that one side is fuzzy in this image once I've merged them.ezucker1 wrote:Even after the images are reversed, I find that they don't make a very good 3D image. I believe this is because of the significant differences in resolution between the two images. We would need to images of comparable resolution to make a better 3D image.
Yeah, it just takes a little practice. What I suggest is look through the screen. That is, let your eyes relax like you're looking into the distance. That will allow the images on the screen to merge, they'll just be out of focus. But once you fuse them, that tends to lock in, and then you can work on bringing your focus back in. And start far from the screen. From 10 feet away, it should be easy. Then work your way closer.Ron-Astro Pharmacist wrote:Yes. I was seeing the star(s) up above the background coming out of the image. I was able to start to view the stereo Pluto as a series of three objects but it hasn't come into 3D yet. I think it's easier for me to spread my gaze outward as you are talking about but more difficult to cross them. It does take some training. Looking at a variety of stereograms seems to be training my eye muscles to do what I want them to.
Actually, the loss of accommodation with age has nothing to do with the muscles that shape the lens, but with the lens itself losing flexibility. So no amount of exercise will help. But there may be pharmaceutical solutions in the near future, or artificial lenses that aren't fixed. Some people who have had cataracts removed have had the lenses replaced with focusable lenses. We're getting there.Wouldn't it be nice to use an exercise like this to help with the curse of old eyes – reading glasses? :evil: Wishfull thinking - that has do another set of muscles but this is still a good for seeing in 3D.
That's an interesting one. Stopping at the first point of intersection yields a 5 point star but if you continue to the next point of intersection, you get a double pointed 5 point star that raises like a tower in the middleRon-Astro Pharmacist wrote:I'm having the same difficulty as some of the others. Is the technique similar to looking at a stereogram?
I can make out the star but not a stereo Pluto.
Not everybody has learned good research skills. This forum is about asking questions, about discussing concepts that may be unfamiliar to many people. Even if those answers might be available elsewhere.3D or not 3D wrote:It is quite amazing that there has been so much confused discussion as to whether this is a stereo pair - or not. Whether the images are the right way around - or not. Clearly before scribbling down their incoherent thoughts, none of these confused people bothered to look up ANYTHING about stereographs, let alone look at Brian May's site dedicated to the subject. Maybe you expect to be spoon fed by APOD to tell you exactly what to do to see the 3D image? Go away and look at all the information available at The London Stereoscopic Company, and in future think very carefully before being so willing to show your complete lack of understanding of a topic, especially when you haven't even bothered to take the first step of looking it up online.
Well, we evolved to look at things ranging in distance from infinity to the tips of our noses. So it's hardly surprising that we can only comfortably move our eyes between parallel and cross-eyed. And parallel implies that the widest images we can readily merge will be spaced no more than our interpupillary distance- a bit over 6 cm for adults.Cousin Ricky wrote:The problem with direct stereographic images is that my eyes simply refuse to merge images more than about 6 cm wide. I think the people who can do “free” viewing with images this large must have double-jointed eyes.
On the other hand, I never have trouble with cross-eyed images.
"APOD: Stereo Pluto" allows one (unnaturally) to see around the backside of a rather large (and distant) Pluto.Chris Peterson wrote:No, the effect is real. Probably the result of this not being a true stereo pair, but rather two images made at different times, with both spacecraft motion and planetary rotation combined. Also, the spacing is very large, which gives a diorama effect that emphasizes the distortion.Coil_Smoke wrote:Is no one else getting the water melon effect ? I have seen this stereo pair twice and saw the same thing.Coil_Smoke wrote:There must be some distortion in generating this stereo pair. When I get the images to merge, a very elongated ' water melon ' shape appears. Like viewing a water melon end on.
Henry beat you to it.Cousin Ricky wrote:Edit: Ah, Neufer, you beat me to it!
Chris Peterson wrote:You don't look cross-eyed with this image. However, training your eyes to view stereo pairs is not harmful. Indeed, there are specific eye exercises that do just that, with therapeutic intent. You can learn to point your eyes independently (like a chameleon) and amaze your friends and possibly advance a career in comedy... all harmlessly.stereouseless wrote:
dear chriss.. i still say its a big waste of time to put these images here... looking crosseyed at something is not good for ones eyes.
. I'll say though that think the melon shape was pervasive in both convex and concave views, but not as clear when concave. 